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Question: I just started to work in big company... Before I worked with software
Friday, January 31, 2003 (01:00:00)
Posted by jalex
Question: I just started to work in big company... Before I worked with
software design myself and developed small programs. Now I hear such terms like
"businnes layer", "presentation layer"...
Has it something to do with Java? Please clarify.
Answer: It has more to do with applications structure and used for design of
large software products. It helps to divide application logic into big logically
independant blocks (layers) that interacts by interfaces. It lets to
develop big software products without knowledge of all details...
I will describe here three layers model:
1. Presentation layer - responsible for content dispalying to user and provides
interface for user - application interaction. It is client in client - server
application.
2. Businnes layer - main logic of an apllication is implemented here: all
required calculations, data validations and so on.
Usually runs on server side in client - server application.
3. Data layer - responsible for data management. This layer provides businness
layer with all data that are processed there and then presented to user by
presentation layer.
Layering of an application lets to change different parts without significant
efforts. For example if data layer operates with a SQL database it can be
switched to Oracle database.
Well planned and structured application will let do it easy.
--
anatoly
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